Process and apparatus for determining the degree of nasality of human speech

ABSTRACT

A process and apparatus is described in which electric signals representative of the sounds emitted from the nose and mouth are utilized to determine the degree of nasality of speech. Separate electric signals are derived from sounds emitted from the nose and mouth and these are compared one to the other and then the resultant signal is compared with a signal representative of a known degree of nasality. A form of apparatus suitable for carrying out the process is disclosed, including means separately to impress the nasal and oral signals onto separately functioning microphones.

United States Paten [191 Fletcher v NASALITY OF HUMAN SPEECH [451 Aug.14, 1973 2,416,353 2/1947 Shipman 179/1 VS Primary Examiner-Kathleen H.Clafiy Assistant Examiner-Jon Bradford Leaheey [76] Inventor: Samuel G.Fletcher, 1919 7th Ave.

South Attorney-Hugh Carter et a].

[22] Filed: Nov. 3, 1971 ABSTRACT [21] Appl. No.: 195,392

A process and apparatus is described in which electric signalsrepresentative of the sounds emitted from the UQS. n e e u s u I t l u tu t s I t e t u s a I n [5 Int. Cl. nasality f SPeech- S p electric igare derived 0 Search 1 VS, from Sounds emitted from the nose and mouthand 128/2 324/77 J these are compared one to the other and then theresultant signal is compared with a signal representative of [56]References Cited a known degree of nasality. A form of apparatus suit-UNITED STATES A N able for carrying out the process is disclosed,including 3,281,534 10/ 1966 Dersch 128/2.1 R means separately toimpress the nasal and oral signals 3,383,466 5/1968 Hillix 179/ 1 SAonto separately functioning microphones. 3,316,353 4/1967 Dersch 179/1SA 3,410,264 11/1968 Frederik 128/2 R 2 Claims, 4 Drawing Figures R t/Frequency comparator %na.7gzer$ Patented Aug. 14, 1973 2 Sheets-Sheet 1uency QIS Z Fre paratar g 9 Fat 0 Z9 calm INVENTOR. Samuel 6. F/ezcherAfforne qs PROCESS AND APPARATUS FOR DETERMINING THE DEGREE F NASALITYOF HUMAN SPEECH This invention relatesto a process and apparatus fordetermining the nasality, or degree of nasality, of human speech.

Heretofore in the diagnosis and treatment of hypernasality, suchcondition generally has been diagnosed merely by having the patientspeak to a human listener, the latterof whom then, perceptually, judgesthe degree of nasality. Such judgment obviously is directly related notonly to the acuity of hearing of the listener, but also to backgroundnoise, the amount of contact which the listener previously had had withthe subject and with other similar subjects, as well as other variousphysical and psychological factors. Therefore, the concept ofdetermining nasality, and prescribing treatment for the same, by patientto listener methods has been found to be inaccurate and ineffective andhas lead to a gross waste of effort both on the part of the patient andthe clinician.

Prior efforts have been made to measure hypernasality by electronicmeans. However, sofaras I am aware such prior efforts have consisted inattempts to utilize the overall sound output from the patient, namely,the sounds emitted from the nasal and oral passages, without attemptingin any effective way to segregate these two sounds, analyze the same asthey relate to their respective frequencies and then compare them.

In view of the foregoing an object of my invention is to provide aprocess for determining the degree of nasality in human speech whichcomprises developing separate electric signals representative of thesounds emitted from the nasal and oral passages of a patient beingtested, said signals also being representative of the nasal resonancefrequency, and then, utilizing said separate signals, to relate the sameto a signal which is representative of a known degree of nasality, thusto obtain an indication of the overall performance of speech, in thesense of nasality.

Another object is to provide a process of the character indicated whichcomprises carrying out the operation during continuous speech of theperson being tested and further, as an aid in speech improvement,continuously to indicate to the person being tested the degree ofpeformance during the entire therapy period.

A further object is to provide apparatus which is capable of carryingout my improved process and which embodies, in particular, a pair ofsound isolated microphones carried by a housing and so relativelyarranged that when the housing is brought into place about the face of aperson the separate sounds from the nasal and oral cavities areimpressed upon the respective microphones, thus initiating and makingpossible the production of the electrical signals with which I start myimproved process.

My invention also is characterized by the provision of apparatus whichis reliable in operation and which is responsive to substantially theentire critical range of resonant frequencies encountered in humannasality.

Apparatus illustrating the constructional features of my invention andwhich may also be used in carrying out my improved process is shown inthe accompanying drawings forming a part of this application in which:

FIG. I is a vertical sectional view, somewhat diagrammatic, andillustrating an internally baffled housing having separate microphonestherein andwhich are adapted to produce signals representative of soundsemitted from the nasal and oral passages of a person being tested;

FIG. 2 is a front elevational view ofthe apparatus shown in FIG. I;

FIG. 3 is a wholly diagrammatic partial wiring dia gram of a portion ofmy improved apparatus; and,

FIG. 4 is a wholly diagrammatic, schematic wiring diagram of theremainder of my improved apparatus.

Referring to the drawings it will first be understood that my improvedprocess starts with and is predicated upon the concept of producingseparate electrical signals which are representative of the soundsemitted from the nasal and oral passages of a person being tested. Tothis end I indicate in FIG. 1 at I0 a housing which may have a circularlower part 11 and an upper, somewhat vertically elongated part 12. Asillustrated in the drawings the lower part 11 provides a chamber 13while the upper part 12 provides a chamber 14. It will be seen, ineffect, that the wall 11a of the device 10, when the device is broughtinto position relative to a human face as shown, separates the acousticoutput of the nose from the mouth.

Associated with the chamber 13" is a microphone 16 while associated withthe chamber 14 is a microphone 17. Sound pervious pads I8 and 19 of foamrubber or the like may be used, if desired.

It will be seen that with the housing 10 in place adjacent the face andwith the baffle: lla contacting the upper lip of the person, soundseminating from the nasal cavities are impressed upon the microphone 17whereas sounds from the oral cavity are impressed upon the microphone16."

Referring particularly to FIG. 3 signals from the microphones l6 and 17are lead through circuits 21 and 22 to the respective frequencyanalyzers 23 and 24. The analyzer 24 is tuned to nasal resonancyfrequency while the analyzer 23 scans the same frequency band in theoral signal.

From the frequency analyzers 23 and 24 the signals are sent through therespective circuits 26 and 27 to the ratio computer, indicateddiagrammatically at 28; In the computer 28 the nasal signal is dividedby the oral signal thus to obtain a quotient signal which is sentthrough appropriate circuits 29 to a ratio threshold detector, themechanism of which is enclosed within the dotted outline 31, FIG. 4.

Circuit 32 leads from the microphone 16 to a voice detector, themechanism of which is included within the dotted outline 33, FIG. 4.

When sound is impressed on microphone. 16 the section of the apparatusindicated by numeral 33 generates a signal which may be denominatedlogic I and this is impressed through circuits 34 onto a time modefunction generator indicated within the box 36. In addition, the signalfrom the voice detector goes to a sixty cycle clock 37 and to a trialmode success-fail detector 38.

From what has been so far described it will be seen that the enumeratedmechanism takes the signals from the nasal and oral passages, convertsthem into electric signals, analyzes the same for respective intensityand frequencies and divides the signal representative of the oral soundinto the signal representative of the nasal sound. This resultant signalis sent through the circuits 29 into the ratio threshold detector 31 andoperates the system either in time or trial mode, depending upon itselected function. The signal from microphone 16 is also brought to thevoice detector 33 to activate the comparative function.

In the ratio threshold detector 31 the signal from circuits 29 is sentto an amplifying circuit which conditions it to proper voltages, by wayof example, from O to 2.4 volts. Also in the section 31 the signal whichhas been thus conditioned is compared with a signal representative of aknown degree of nasality, which by way of example may be 1.8 volts. Thecomparison signal is lead through circuits 31a to the 60 cycle clock 37,the time mode function generator 36 and to the trial mode success-faildetector 38.

Simultaneously with the foregoing the signal through the circuits 32coming from microphone 16 are fed to the voice detector 33 whichincludes an isolation amplifier and sensitivity control therefor, arectifier, a filter and a threshold detector. The signal coming throughcircuits 32 from microphone 16 is generally on the order of about to 0.8volts AC, peak. As before stated, the output through circuits 34 fromsection 33 go to the clock 37, the time mode function generator 36 andtrial mode success-fail detector 38.

From what has been so far described it will be seen that the apparatusprovides means to determine during the trial period, (namely, during thetime the person is speaking) whether the degree of nasality hasdecreased below the selected level to which the ratio signal in circuits29 are being compared.

The trail mode success'fail detector 38 receives the signal from thevoice detector 33 and the ratio threshold detector 31 through circuits41 to an eight bit shift register indicated at 42. The ratio signal isdelivered through circuits 43 to a two input NAND gate 44 and a circuit46 leads from the gate 44 to the input of a J-K flipflop 47. Thus, whenthe signal in circuits 29 indicate a degree of nasality below thecomparison level, the unit 47 sends a signal through circuits 48 toanother two input NAND gate 49. When a person stops speaking, forinstance at the end of a word, the device 49 gates out a signal which issent to the success counting devices indicated in part by the numeral 51and circuits 52. The unit 51 may indicate success in the form of asuccession of lights, and so forth. In addition, a circuit 53 may leadto a counter or counters to totalize the number of successes.

In view of the foregoing it will be seen also that various ancillaryequipment may be associated with my apparatus. By way of example one maydisplay to the person being tested a succession of lights, or otherindicia, indicating to him his repeated success or repeated failure,with each attempt to speak a given sentence, phrase, word or the like.

In actual practice my improved process and apparatus have proven to beextremely beneficial in the scientific diagnosis and treatment ofhypernasality. By my improved process people of all ages, that is,children as well as adults have been enabled to reduce theirhypernasality to acceptable levels within a very short time as comparedto months and even years through traditional observation and treatment.I have thus reduced the science of determining and treating hypemasalityfrom an individual appraisal basis to that of an objective, accuratelydeterminable basis. My invention provides a fixed standard against whicha person afflicted with hypemasality may be advised, continuously, as hespeaks, of the degree of the same and the improvement which he makeswhile undergoing observation and test- While I have shown my inventionin but one form, it will be obvious to those skilled in the art that itis not so limited but is susceptible of various other changes andmodifications without departing from the spirit thereof.

What I claim is:

1. In apparatus for analyzing continuous human speech to indicate thedegree of nasality thereof comprising:

a. means to produce separate electric signals directly from the soundsemitted from the nasal and oral passages of a person being tested,

b. means to which said signals are separately fed and effective to emitseparate signals representative of the proportionate intensity of eachsignal within a predetermined frequency range,

0. means to which the signals from the means set forth in (b) above arefed and effective to generate another signal which represents the ratioof said signals which ratio is representative of a known degree ofnasality d. means to compare said ratio signal to a signal representinga known degree of nasality, and

e. indicating means responsive to the signal obtained from the means of(d) above.

2. Apparatus as defined in claim 1 in which the means set forth in (a)of claim 1 comprises an internally baffled housing disposed when placedadjacent the face of a person to provide a pair of sound chambers, oneof which chambers communicates with the nasal passages and the other ofwhich communicates with the oral passage, and microphones in each ofsaid chambers by which the sounds emitted from the nose and mouth arecaused to produce separate electric signals.

1. In apparatus for analyzing continuous human speech to indicate thedegree of nasality thereof comprising: a. means to produce separateelectric signals directly from the sounds emitted from the nasal andoral passages of a person being tested, b. means to which said signalsare separately fed and effective to emit separate signals representativeof the proportionate intensity of each signal within a predeterminedfrequency range, c. means to which the signals from the means set forthin (b) above are fed and effective to generate another signal whichrepresents the ratio of said signals which ratio is representative of aknown degree of nasality d. means to compare said ratio signal to asignal representing a known degree of nasality, and e. indicating meansresponsive to the signal obtained from the means of (d) above. 2.Apparatus as defined in claim 1 in which the means set forth in (a) ofclaim 1 comprises an internally baffled housing disposed when placedadjacent the face of a person to provide a pair of sound chambers, oneof which chambers communicates with the nasal passages and the other ofwhich communicates with the oral passage, and microphones in each ofsaid chambers by which the sounds emitted from the nose and mouth arecaused to produce separate electric signals.